Sleep duration and biomarkers of inflammation in African American and white participants with a parental history of Alzheimer's disease

Introduction: African Americans (AA)s have worse inflammation, worse sleep, and a greater incidence of Alzheimer's disease (AD) compared to whites; however, no studies have examined associations between biomarkers, sleep, and cognition, and differences by race. Methods: Seventy-six cognitively normal, middle aged (45–65 years) adults with a parental history of AD were included in this study. Associations between biomarkers (tumor necrosis factor-α [TNF-α], interleukin-10 [IL-10], intercellular adhesion molecule-1 [ICAM-1],, and C-reactive protein [CRP]) and self-reported sleep or cognition measures, were assessed. Results: Average sleep duration was significantly lower for AA versus whites (average[SD]) in hours: 6.02(1.18) versus 7.23(0.91), P =.000004). We found a statistically significant association between plasma IL-10 and sleep duration (Spearman's ρ = 0.26, P =.04) and CSF ICAM-1 and sleep quality (Spearman's ρ = 0.30, P =.03). Discussion: Longer sleep duration is positively associated with plasma IL-10 levels irrespective of race. Sleep quality was positively associated with CSF ICAM-1 only in African Americans.